TW200936309A - Electrolitic composite abrasion method and abrasion method - Google Patents

Abstract

The present invention provides an electrochemical polishing method capable of increasing a polishing speed while preventing excessive polishing, such as dishing or erosion. In the electrochemical polishing method, when a voltage applied to a conductive film formed on the surface of a substrate is increased at a contact surface pressure of 0 between the surface of the substrate and a polishing pad, a voltage at a first change point C that allows a current density to start to decrease after an increase is referred to as a minimum voltage. In addition, when the voltage is increased at a contact surface pressure having a finite value, a voltage at a second change point B that allows the current density to be maintained constant after the decrease is referred to as a maximum voltage. In this case, the surface of the conductive film is polished while maintaining the voltage to be not lower than the minimum voltage and not higher than the maximum voltage. Further, the present invention provides an electrochemical polishing method capable of rapidly removing a conductive film in regions other than a contact plug or wiring line forming region while preventing excessive polishing, such as dishing or erosion. In the electrochemical polishing method, in a step of increasing a voltage, when the voltage is increased at a contact surface pressure of 0, a voltage at a first change point C that allows a current density to start to decrease after an increase is referred to as a threshold voltage, and the voltage is increased such that a voltage in a region in which a barrier film is exposed is higher than the threshold voltage.

Description

200936309 • VI. Description of the invention: [Technical field to which the invention pertains] The present invention relates to an electrolytic composite polishing method and a polishing method. The present application claims priority from Japanese Patent Application No. 2007-264468, filed on Oct. 10, 2007, and the priority of the entire entire entire entire entire entire entire entire entire entire entire entire content The content of the two applications. [Prior Art]

A wiring forming process for a semiconductor device has been conventionally used as a damascene process in which wiring is buried in a wiring recess such as a trench or a via hole provided in an insulating film. metal. This damascene process is generally carried out in the following manner: as shown in FIG. 6A, an insulating film formed of a so-called low dielectric value (Low-k) material or the like on the substrate (interlayer In the insulating film 62, a "contact plug" or a recess for forming a wiring (hereinafter referred to as a recess = 卩) 63' is formed, and then a titanium nitride is formed on the entire surface of the interlayer insulating film including the recess rib. A barrier metal film (which is a barrier film) 64 is formed, and a metal conductive film (hereinafter referred to as "conductive film") 66 formed by the crane is formed on the surface of the barrier film 64, and is recessed. ^ Embedded human metal conductive material. At this time, the surface of the conductive film (10) forms a recess 67 similar to the recess 63 of the plurality of layers. Then, the excess conductive (four) and the barrier film 64 on the outer side of the recess 63 are removed. The removal of the formed conductive crucible 66 is performed by a chemical machine (the CMP system is as shown in Fig. u, while the abrasive poly 320663 4 200936309 w (slurry) 52 is supplied to the conductive film on the surface of the substrate W, The surface of the substrate W is pressed against the polishing pad 101 while the substrate W and the polishing pad 101 are relatively moved, and the surface of the conductive film is polished (see, for example, Non-Patent Document 1, that is, the Sakamoto Industrial Survey, published in December 2000, edited by Toshihiro Jun "Detailed Semiconductor CMP Technology", pp. 277 to 284.) The slurry 52 contains abrasive grains and an oxidizing agent, whereby the oxidizing agent forms a tungsten oxide film on the surface of the conductive film 66 shown in Fig. 6A. The tungsten oxide film of the upper portion of the film (the outer side of the concave portion 67) is removed by contact with the polishing pad, so that the conductive film 66 of the upper portion of the film is polished. On the other hand, the lower portion L of the conductive film is formed. Since the tungsten oxide film (inside of the concave portion 67) is not in contact with the polishing pad, it is not removed, and the conductive film 66 in the lower portion is not subjected to polishing. Thereby, the step of the surface of the conductive film 66 is made (recessed portion 67) ) Eliminated. In order to increase the polishing rate, in addition to supplying a slurry containing a high concentration of abrasive grains, it is necessary to have a high polishing pressure. However, in this case, the surface of the conductive film is liable to be damaged by scratches or the like. (dishing) (over-polishing of the conductive film). In addition, it is also polished to an interlayer insulating film that should not be polished, so that there is a problem that abrasion (over-polishing of the insulating film) is likely to occur. It is an object of the present invention to provide an electrolytic composite polishing method and a polishing method capable of preventing over-polishing of dishing, abrasion, and the like, and rapidly eliminating the surface of the conductive film. Further, although "electrolytic composite grinding" is regarded as The technique of "electrolytic polishing" is included in the "electrolytic polishing". However, the term "electrolytic composite polishing" is used in this specification. In addition, the so-called electrolytic polishing is referred to as 5 320663 200936309. The electrolyte causes the conductive material to interact with the opposite phase to add 4 electric (4) grinding; conduction, by means of electrochemical mechanical research In addition, the chemical_heart also includes the development of a large-scale integrated circuit (LSI) device (the flattening of the interlayer film of the planarizati〇n wiring), which is developed by using the solid-liquid reaction wet of the working blood slurry. The mechanical chemical processing method of the present invention is a polishing method in which an electrolytic solution is used to electrically conduct a conductive substance and a counter electrode to process a conductive substance by electrochemical action and mechanical action. The second object is to provide an electrolytic composite polishing method which can prevent the dishing of the dish and the excessive polishing of the abrasive, and can quickly remove the conductive film outside the connection region of the connection and the wiring. [Invention] The inventor of the present invention found The following matters. That is, when the electrolyte having a pH of 4 to 10 is brought into contact with the electroconductive film and then the applied voltage is increased, the current density is rapidly changed at the pre-existing voltage. When the applied voltage to the conductive film is increased from 0, the current density increases in proportion to the voltage, but when the voltage exceeds the first change voltage of the first change point (for example, point A of FIG. 7) and continues to increase, The current density will decrease from increasing to decreasing. Then, when the voltage exceeds the second change voltage of the second change point (e.g., point B of Fig. 7) and continues to increase, the degree of decrease in current density decreases, and then the current density does not decrease to become a substantially constant value. Such a phenomenon is conceivable because when a voltage lower than the first varying voltage is applied, a surface of the conductive film is formed with a protective film which is soluble for the electrolytic solution, and when a voltage equal to or higher than the second varying voltage is applied, the conductive film is conductive. The surface of the film is formed with a protective film that is insoluble to the electrolyte. The above-described tungsten polishing method by CMP is known, because the use of an acidic slurry of pH < 4 to form a relatively thick tungsten oxide film, and mechanically grinding the mechanism of the tungsten oxide film, the polishing rate becomes low. Hey. Therefore, in order to increase the polishing rate, a method in which a high polishing pressure is applied in addition to a slurry containing a high concentration of abrasive grains is considered, but it is known that this method also causes a problem. The inventors of the present invention have found that the first and second varying voltages described above vary depending on the contact surface pressure of the substrate and the polishing pad. The higher the contact surface pressure, the larger the first and second varying voltages, and the greater the current density. When a voltage equal to or lower than the first varying voltage (e.g., the voltage at point C in Fig. 7) is applied when the contact surface pressure is set to 0, the entire surface of the conductive film forms a protective film which is soluble for the electrolytic solution. Further, when a voltage equal to or higher than a second varying voltage (for example, the voltage at point B in FIG. 7) is applied when the contact surface pressure is set to a finite value, the entire surface of the conductive film forms a protective film which is insoluble to the electrolytic solution. . These phenomena are the same regardless of the surface of the conductive film. Therefore, an aspect of the present invention is configured such that when the voltage is increased in a state where the contact surface pressure is 0, the current density is changed from an increase to a decrease voltage (for example, the voltage at point C in FIG. 7). As the minimum voltage, when the voltage is increased in a state where the contact surface pressure is a finite value, the current density is decreased from the increase to the voltage that is no longer reduced (for example, the voltage at point B in FIG. 7) as the maximum voltage. The surface of the conductive film is polished while maintaining the voltage above the minimum voltage and below the maximum voltage. 7 320663 200936309 According to this configuration, in the case where there is a step on the surface of the conductive film, the contact surface of the conductive film and the polishing pad is a finite upper portion (for example, above the 8b diagram • kj H) a Ha-dissolving protective film , the protective film will be completely removed by grinding #, the contact surface pressure between the conductive film and the polishing crucible is lower than the lower portion C, and the lower portion of the 8B ® lower portion L) forms an insoluble protective film, and the protective film does not Will be ground and left behind. Thereby, the conductive film is promoted to dissolve in the electrolytic solution in the upper portion, and the dissolution of the conductive film is suppressed in the lower portion. Therefore, the step difference of the surface of the conductive film can be quickly eliminated. Outside β π 3 , the polishing speed of the lower portion of the protective film is relatively slow, so that the conductive film is less likely to be dished. Further, since the polishing rate of the upper portion can be suppressed by adjusting the applied voltage, the contact surface pressure between the polishing crucible and the conductive film can be set lower, and the shoe grinding can be suppressed. In addition, an aspect of the present invention is configured such that when the voltage is increased in a state where the contact surface is pressed, the current density is changed from an increase to a decrease voltage (for example, point c in FIG. 7). The voltage is used as the minimum voltage 10^ to increase the voltage increase in the state in which the contact surface pressure is finite, and the IL temperature is reduced from the increase to the voltage that is no longer reduced (for example, FIG. 7B). The point voltage is the maximum voltage, and the surface of the conductive film is polished while maintaining the voltage above the minimum voltage and below the maximum voltage. According to this configuration, in the case where there is a step on the surface of the conductive film, the contact surface of the conductive film and the polishing pad can be pressed to a finite value, and the current density and the contact surface pressure of the upper portion of the segment such as the upper portion H) of FIG. 8B are pressed. The difference in current density between the lower portion (for example, the lower portion L of the eighth drawing) is larger. This current density is 320663 8 200936309 ► The difference corresponds to the difference in the polishing speed between the upper and lower sections of the conductive film. Since the current density is high, for example, the polishing rate is large, the difference in current density is large, which means that the difference in polishing speed is large. Further, the low current density corresponds to a small difference in polishing speed. Therefore, as long as the current density is appropriately controlled, the polishing rate can be controlled so that the step of the surface of the conductive film can be quickly eliminated. In one aspect of the invention, the polishing rate of the foregoing conductive film is controlled by adjusting the pH of the foregoing electrolyte. © Since the pH of the electrolyte increases, the dissolution of the conductive film is promoted. Therefore, the polishing rate of the conductive film can be controlled by adjusting the pH of the electrolyte. In one aspect of the invention, the electrolyte solution contains an additive which reacts with the conductive film to form an electrically insulating substance, and the polishing rate of the conductive film is controlled by adjusting the concentration of the additive. Since the concentration of the aforementioned additive becomes stronger, a strong protective film is formed and is not easily removed by grinding, so that the polishing rate of the conductive film can be controlled by adjusting the concentration of the aforementioned additive. In one aspect of the invention, the polishing rate of the conductive film is controlled by adjusting the rotational speed of the polishing pad. Since the polishing film is removed as the rotation speed of the polishing pad is increased to promote the dissolution of the conductive film, the polishing speed of the conductive film can be controlled by adjusting the rotation speed of the polishing pad. One of the samples of the present invention is a polishing method having a polishing step of polishing the substrate by pressing the substrate surface to a polishing crucible with a predetermined contact surface pressure to move the substrate and the polishing pad (4). 320663 9 200936309 The conductive film on the surface, the polishing method is characterized in that the electrolyte is brought into contact with the conductive film while the substrate is moved relative to the polishing pad while the contact surface is sturdy. When a voltage is applied and the voltage is increased, the wire is decreased from an increase to a voltage which is no longer reduced as a threshold voltage ' ^ before the aforementioned red sequence, the substrate is not in contact with the polishing pad A protective film forming step of forming a protective film on the surface of the conductive film by bringing the electrolytic solution into contact with the conductive film while applying a voltage equal to or higher than the threshold voltage. According to this configuration, a protective film which is conductive to the electrolytic solution is formed by applying a voltage of a threshold voltage in the protective film forming step. In the xi (4) research red order, the medical crane film will be removed by grinding, and the protective film formed in the lower part of the enamel film is formed in the tomb of the tomb wax and is left to be ground. Thereby, the step difference of the surface of the conductive film can be quickly eliminated. In the aspect of the invention, the polishing step is a chemical mechanical polishing step or an electrolytic composite polishing step. Since the protective film is formed immediately after the polishing step, the step of the surface of the conductive film can be quickly eliminated regardless of the case of any of the mechanical polishing and electrolytic polishing methods. The inventors of the present invention found that by adjusting the potential of each part of the surface of the substrate, the polishing unevenness of each part of the substrate can be controlled. In other words, there is a difference in resistance between the metal film formed on the surface of the substrate (i.e., the money of the lower layer) and the conductivity of the upper layer. The difference is used to adjust the potential of each portion of the substrate. A voltage is applied from the application point of the surface of the metal film to the surface of the substrate, and in the case where the substrate is completely covered with a conductive film, the entire substrate will have substantially equal voltages. However, when the conductive film in the vicinity of the voltage application point is removed to expose a part of the film, the voltage distribution on the surface of the substrate changes. In other words, since a voltage is applied to the =electrode film through a base film having a higher electric resistance than the electroconductive film, the voltage applied to the electroconductive film is lower depending on the distance from the application point. Therefore, in one aspect of the present invention, by contacting the electrolyte with a metal film formed on the surface of the substrate and applying a voltage to the metal film, the substrate is ground to a predetermined contact surface M. The electrolytic composite polishing method for polishing the surface of the metal film while the substrate is simultaneously moved relative to the front ruthenium polishing pad, wherein the electrolyte solution is at a pH of 4 to 1 Å, and the metal film is formed by the bottom of the lower layer. The film and the electric resistance are formed by an 'electrode film smaller than the upper layer of the underlayer film, and the electrolytic composite polishing method has a step of removing the conductive film in the vicinity of the application point of the conductance and exposing the underlying film, and pressing and a step of increasing or exposing the base film to increase the voltage, and the step of: increasing the voltage in a state in which the substrate and the polishing pad are opposed to each other while the contact surface pressure is zero. The voltage from the increase to the decrease in the current density is used as the threshold voltage, and the voltage is increased until the voltage of the exposed region of the underlying film exceeds the aforementioned threshold voltage. According to this configuration, since the current density is reduced when the voltage of the exposed portion of the underlayer exceeds the threshold voltage, the polishing rate of the conductive film is lowered. Therefore, even if there is a conductive film which becomes a contact plug or a wiring in the exposed region of the under film, it is difficult to form a dish on the surface of the conductive film. 11 320663 200936309 Depression 〃 In addition, since the electrochemical dissolution is used for the polishing Therefore, it is not necessary to use a polishing system having a high abrasive grain concentration as in the prior art, and it is not necessary to perform polishing at a high contact surface pressure, so that the ratio of the mechanical polishing action is lowered, and the occurrence of abrasion can be prevented. In addition, the contact surface pressure has a finite value such as 4 Psi. ^ On the other hand, 'the area where the resistive film is smaller than the base film remains, because the voltage applied to the conductive film depends on the distance from the exposed portion of the base film, so the current density is higher than the base film exposed (four). State. Therefore, the polishing will continue in the area where the electric film remains, so that it is possible to quickly remove the electric conductivity while suppressing the damage such as scratches and the dishing, and in addition, in one aspect of the present invention, the foregoing is improved. In the process of voltage, when the voltage is increased in a state where the contact surface pressure is a finite value, the electric power is reduced from the increase to the voltage that is no longer reduced as the maximum electricity house, and the voltage is increased to the bottom. The electric power of the area other than the exposed area of the film exceeds the aforementioned threshold surface by the maximum electric power. ❿=According to this, 'the area outside the exposed area of the base film, that is, the area where the == exists, is set to exceed the threshold value and will be used as the contact SI before: even if the conductive film remains There is a case where there is a conductive film which is contact plug or wiring, and high electric power can be maintained. = Read state until the conductive film is ground to the same level as the bottom level. This area: Tan: The conductive film remains. In the region where the polishing is continued to expose the film, in the present invention, the bottom portion 320663 12 200936309 is configured to apply the contact surface pressure of the material substrate (4) region of the application near the postal field t to be The aforementioned contact surface pressure in the region near the aforementioned application point is high.

According to this configuration, when the contact surface pressure of the spot material to be applied is higher than the contact surface in the region other than the region near the application point, the vicinity of the application point is compared with the region other than the region near the application point. The grinding of the area will be promoted' so the conductive film of the area will be removed first. Since b' can obtain a voltage distribution which is applied to the metal film at the vicinity of the application point, the voltage 屡' decreases as the distance from the portion increases. Therefore, it is possible to remove the remaining conductive film _ with high precision after the base film is exposed. Further, in one aspect of the invention, the step of exposing the bottom rim is such that the counter electrode facing the substrate is composed of a plurality of _ small electrodes arranged concentrically on the same plane. The money electrode is controlled to control the voltage of the divided electrode in such a manner that the frequency of the outer surface of the substrate is higher than the outer portion of the substrate. According to this configuration, by controlling the voltage of the divided electrode so that the polishing rate is faster in a procedure in which the frequency toward the outer portion of the substrate is higher, the residual film of the conductive film can be made from the outer portion toward the center portion. The thicker and thicker state is polished, and the base film of the peripheral portion of the substrate is surely exposed. Further, in one aspect of the invention, the polishing step is performed while measuring the residual film thickness of the conductive film by an eddy current method. According to this configuration, by measuring the residual film thickness of the conductive film by the eddy current method, it is possible to perform film thickness measurement with high precision. 320663 13 200936309 Further, in one aspect of the invention, the conductive film is a tungsten film. According to this configuration, by using the tungsten film as the conductive film, the adjustment of the polishing rate as described above is facilitated. Further, an aspect of the present invention is to press the surface of the substrate to the polishing pad with a pre-twisted contact surface pressure while bringing the electrolytic solution into contact with the metal film formed on the surface of the substrate and applying a voltage to the metal crucible. An electrolytic composite polishing method for polishing the surface of the metal film by moving the substrate and the polishing pad, wherein the electrolyte solution is pH 4 to 1 Å, and the metal film is composed of a lower layer and a resistor. The electroconductive composite polishing method includes a step of arranging the application point of the voltage on a peripheral portion of the substrate, and removing the conductive film on the peripheral portion to expose the underlayer, and After this step, the step of applying the voltage is moved from the peripheral edge portion of the substrate to the central portion to expose the underlayer film. According to this configuration, after the base film is exposed, the voltage application point 10 is moved from the peripheral edge portion of the substrate to the center portion, whereby the voltage in the bottom exposed region can be maintained at a high level. Thereby, even in the case where the conductive film to be contact plug or wiring exists in the exposed region of the under film, it is difficult to form a dish-shaped recess on the surface of the conductive film. Further, an aspect of the present invention is to press the surface of the substrate to a polishing pad with a predetermined contact surface pressure while bringing the electrolytic solution into contact with the metal film formed on the surface of the substrate and applying a voltage to the metal film. An electrolytic composite polishing method for moving the surface of the metal film before polishing, and the surface of the metal film before polishing, wherein the electrolyte solution is 4 to 1 ,, 320663 14 200936309 * the metal lanthanum is a bottom film of the lower layer and a conductive film having a lower electric resistance than the base film, wherein the electrolytic composite polishing method has a step of disposing the voltage applied to a peripheral portion of the substrate, and first removing the conductive film on the peripheral portion to expose the base film a step of moving the voltage application point from the peripheral edge portion of the substrate to the center portion after the step to expose the base film, and a step of increasing the voltage after the base film is exposed or exposed, thereby increasing the voltage In the step of moving the substrate and the polishing pad relative to each other, the contact surface pressure is increased to zero. © When the voltage is applied, the current density changes from increasing to decreasing as the threshold voltage, and the voltage is raised to such a value that the exposed area of the underlying film exceeds the threshold voltage. According to this configuration, by moving the voltage application point from the peripheral edge portion of the substrate to the center portion, the voltage in the exposed portion of the base film can be equal to or higher than the threshold voltage even if the voltage is not largely increased. Therefore, even if a conductive film which will become a contact plug or a wiring exists in the exposed region of the under film, it is difficult to form a dish-shaped recess on the surface of the conductive film. [Embodiment] Hereinafter, one or more embodiments of the present invention will be described in detail with reference to the drawings. (Substrate Processing Apparatus) Fig. 1 is a plan view showing an arrangement configuration of a substrate processing apparatus including an electrolytic composite polishing apparatus according to the present invention. The substrate processing apparatus 3 is provided with a loading/unloading stage (1〇ad/unl〇ad stage) in which the substrate 匣 204 is accommodated. A plurality of substrate signals can be stored in the substrate 匣 204. The traveling mechanism 2 〇〇 15 320663 200936309 is provided with a transport robot 202 having two machine-aged flying bodies, so that the transporter 202 can reach the substrates (4) 4 in the loading/unloading station. Traveling The traveling mechanism consisting of a linear motor is used. By using a running mechanism composed of a linear motor, even if the diameter is large and the weight of the substrate is, for example, 450 wafer diameter (four) wafers, high-yield and stable conveyance can be performed. On the extension line of the running mechanism _, there is disposed π Μ which is a film thickness measurement on the substrate after grinding or polishing, that is, an in-line thickness monitor (In-line Thickness Monit〇r) 224.

Two money units are disposed on the opposite side of the traveling mechanism of the transport robot 202. The respective units 212 are disposed at positions reachable by the robot of the transport robot 202. Further, between the two drying units 212, a substrate station having four substrate mounting tables is disposed at a position where the transfer robot 2 () 2 can reach. A transfer robot 208 is disposed at a position where each of the drying unit 212 and the substrate station 206 can be reached. A washing unit 214 adjacent to the drying unit 212 is disposed at a position reachable by the robot arm of the transfer robot 208. The rotary conveyor 210' is disposed at a position where the robot arm of the transport robot 2G8 is reachable, and two electrolytic composite polishing apparatuses 25A of the present embodiment are disposed at a position where the substrate can be conveyed and received with the rotary conveyor 21. Each of the electrolytic composite polishing apparatuses 250 includes a substrate head 1, a polishing table 1A, a polishing pad 101 (see FIG. 2, etc.), and an electrolyte supply nozzle (electrolyte supply unit) that supplies an electrolytic solution to the polishing pad 1〇1. A dresser 218 for dressing the polishing pad 101 and a water tank 222 for cleaning the dresser 218. 16 320663 200936309 (Electrolysis composite grinding device) 2Fig. 2 Dry 2 Grinding ^ 250 schematic diagram. If the first = Λ: 1 is connected to the substrate head through the universal joint portion 1 = = the base f-head drive shaft 11 is coupled to the substrate head gas red m, : = 2 U1 is fixed to the swing arm 110. The substrate head driving shaft η is moved by the substrate head with the milk red 111, and the C2 spleen 151 is moved downward to lift the substrate head 1 as a whole, and the buckle which is fixed to the lower end of the substrate head body 2 (shirt ^咖) Ο 3 Press to the polishing table. The substrate gas ray is connected to the compressed air source 12 through the regulator, and the fluid pressure of the pressurized air supplied to the substrate head cylinder 1U can be adjusted by the regulator rei. The ring 3 presses the pressing force of the polishing pad ιοί. The substrate head drive shaft 11 is coupled to the rotating cylinder 112 via a key (not shown). The outer circumference of the rotating cylinder 112 is provided with a timing pulley 113. The swing head arm 110 is fixed with a base head motor 114 as a rotation drive unit, and the timing pulley 113 is connected to the timing pulley jig provided in the base head motor 114 through the timing belt 115. Therefore, the base head motor 114 is driven. Rotating, under the transmission of the timing pulley 116, the timing belt 115 and the timing pulley 113, the rotating cylinder 112 and the substrate head driving shaft 11 are integrally rotated to rotate the substrate head 1. The swing arm 110 is fixed and supported by The frame shaft 117 is supported, (substrate head). Fig. 3 is a cross-sectional view showing the substrate head 1. Fig. 4 is a bottom view of the substrate head 1 shown in Fig. 3. As shown in Fig. 3, the substrate head is shown. 1 has: internal containment space A cylindrical container-shaped substrate head body 2 and a solid 17 320663 200936309 - a buckle 3 fixed to the lower end of the substrate head body 2. The substrate head body 2 is made of a material having high strength and rigidity such as metal or ceramic. The buckle 3 is formed of a highly rigid resin such as PPS (polyphenylene sulfide) or an insulating material such as ceramic. The substrate head body 2 is provided with a cylindrical container-shaped case portion 2a and embedded. An annular pressure piece support portion 2b that is fitted to the inner side of the cylindrical portion of the case portion 2a, and an annular seal portion 2c that is interposed on the outer peripheral edge portion of the upper surface of the case portion 2a. The lower jaw portion of the buckle 3 on the lower surface of the casing portion 2a of the main body 2 protrudes inward. Further, the buckle 3 and the substrate head body 2 may be integrally formed with the center portion of the casing portion 2a of the substrate head body 2. The substrate head drive shaft 11 is provided, and the substrate head main body 2 and the substrate head drive shaft u are coupled by a universal joint portion 10. The universal joint portion 1 is provided with a substrate head body 2 and a substrate head drive shaft u. Spherical bearing mechanism capable of tilting motion with each other, and a woman who will be a substrate __ U Transferring to the rotation transmitting mechanism of the substrate head body 2 to transmit the pressing force and the rotational force of the substrate head driving shaft to the substrate head body while allowing the substrate head reading 2 to move obliquely with respect to the four members of the substrate head driving shaft 2. The spherical surface bearing mechanism is formed by a spherical recessed portion 11a formed on the lower surface of the substrate head drive shaft 11, and formed in the center of the upper surface of the housing portion 3, the moxibustion portion 2d, and the two concave portions Ua. Between 2d and formed by the bearing ball 12 formed by the ceramic material, the rotation transmission name is driven by the driving pin (not shown) fixed to the substrate head drive shaft 11 and the driven body part%. Not numb). Because even if the base (4) 320663 18 200936309 • the body 2 is tilted, the driven pin and the drive pin can move relative to each other in the up and down direction, so that the contact points between the two recesses and the bearing ball are offset, but the 'rotation transmitting mechanism can be surely The torque of the substrate head drive shaft n is transmitted to the substrate head body 2. The substrate head body 2 and the space formed by the inside of the buckle 3 integrally fixed to the substrate head body 2 are housed in an elastic pad 4 and a ring that abuts on the substrate W such as a semiconductor wafer held by the substrate head. The retaining ring 5 and the approximately disc-shaped refreshing plate supporting the elastic crucible 4 (the curry mountain (6) β 6. The outer peripheral portion of the elastic crucible 4 is clamped to the retaining ring 5 and fixed to the lower end of the retaining ring 5 Between the clamping plates 6, the lower surface of the clamping plate 6 is covered. Thereby, a space is formed between the elastic pad 4 and the clamping plate 6. The elastic between the retaining ring 5 and the substrate head body 2 is elastic. a pressure piece 7 formed of a film. The pressure piece 7 is made of, for example, Ethylene-Propylene Diene Monomer rubber (EPDM), p〇lyUrethane rubber, 矽Rubber (siUc〇nrubber), etc. The rubber sheet is formed of a rubber material having good strength and durability. The pressure piece 7 has one end sandwiched between the casing portion 2a of the substrate head body 2 and the pressure piece supporting portion 2b, and the other end of which is sandwiched at the upper end of the retaining ring 5. The portion 5a is fixed between the portion 5a and the stopper portion 5b. By the substrate head body 2, the clamping plate 6, and the protection The ring 5 and the pressure piece ' form a pressure chamber 21 inside the substrate head body 2. As shown in Fig. 2, a flow path 31 composed of a tube, a joint, or the like is extended from the pressure chamber 21, and the pressure chamber 21 is provided. The regulator RE2 in the flow path 31 is connected to the compressed air source 120. Further, the pressing piece 7 shown in Fig. 3 is formed of an elastic body such as rubber, 19 320663 200936309, and the pressing piece 7 is sandwiched. When the buckle 3 and the substrate head body 2 are fixed between each other, the lower surface of the buckle 3 may not have a desired plane due to the elastic deformation of the pressing piece 7 which is itself an elastic body. Therefore, in order to prevent this. In the present embodiment, the pressing piece supporting portion 2b is separately provided, and the pressing piece 7 is sandwiched between the case portion 2a of the substrate head main body 2 and the pressing piece supporting portion 2b, and is fixed to the elastic pad. 4, a center bag (center portion abutting member) 8 as an abutting member abutting against the elastic pad 4, and an annular pipe (outer abutting member) 9 are provided inside the space between the holding plate 6. In this example, as shown in FIGS. 3 and 4, the center bag 8 is disposed under the holding plate 6. The central portion, the annular tube 9 is disposed on the outer side of the central bag 8 so as to surround the central bag 8. Further, the elastic pad 4, the central bag 8 and the annular tube 9 are similar to the pressure piece 7 by, for example, three-way B. A rubber material having good strength and durability such as propylene rubber (EPDM), polyurethane rubber or ruthenium rubber is formed. As shown in Fig. 3, the space e formed between the holding plate 6 and the elastic pad 4 is in the center. A plurality of spaces are formed under the partition of the bag 8 and the annular tube 9, a pressure chamber 22 is formed between the central bag 8 and the annular tube 9, and a pressure chamber 23 is formed outside the annular tube 9. The central bag 8 is connected with the elastic pad 4 The elastic film 81, which abuts on the upper surface, is configured to detachably hold the central bag holder (holding cymbal) 82 of the elastic film 81. The central bag holder 82 is formed with a screw hole, and the screw 55 is locked to the screw hole to mount the center bag 8 = to the lower surface of the tablet 6. The middle portion of the pressure film 81 and the central bag holder 82 are formed with a central portion pressure chamber ice 20 320663 200936309 Similarly, the annular tube 9 is a strong film 9 that abuts against the upper surface of the elastic pad 4. And a ring member (holding portion) for holding the elastic film 91 in a detachable manner. (4) The configuration pipe holder 92 is formed with a screw hole 92a. [The screw 56 is locked to the screw hole (4), and the ring pipe can be mounted. The lower surface of the holding plate 6 is attached in a disassembled manner. The annular tube 9 is formed with an intermediate portion pressure 25 25 by means of the elastic film 91 and the annular tube holder 92, 23, a central pressure chamber 24, and a pressure chamber at the intermediate portion, respectively, and a pipe and a joint. The flow path of the configuration is connected from %%,%, and the pressure chambers 22 to 25 are connected to the compressed air source 12〇 as a supply source through the regulators (4), Cong, RE5, and halls provided in the respective flow paths 33 to %. . Further, the flow paths 31, 33 to 36 are connected to the respective regulators RE2 to RE6 through a rotary joint (not shown) provided at the upper end portion of the substrate head drive shaft 11#. Then, the pressurized fluid or the like pressurized air or the like is supplied to the pressure chamber 21 and the pressure chambers 22 to 25 above the holding plate 6 via the winding paths 31, 33 to 36 which communicate with the respective sound chambers. As shown in Fig. 2, the pressure of the pressurized fluid supplied to each of the pressure chambers can be adjusted by arranging the regulators RE2 to the legs on the flow paths 31, 33 to 36 of the pressures of 21 to 25. Thereby, the pressure inside the respective pressure chambers 21 to 25 can be independently controlled, or the pressure to the inside of 21 to 25 can be atmospheric pressure or vacuum. Thus, the pressures inside the pressure chambers 21 to 25 can be independently changed by the regulators RE2 to RE6, and the substrate ψ can be pressed to the polishing pad by the elastic pads for each of the substrates w (divided regions). I press 320663 200936309. As shown in Fig. 3, a plurality of convex portions 42 are erected from the holding plate 6 toward the pressure chambers 22, 23. The front end of the convex portion 42 is exposed to the elastic pad 4 through the opening portion 41. In addition, a flow path 43 extending from the front end surface of the convex portion 42 is provided, and the flow path 43 is connected to the vacuum source 121 shown in Fig. 2. Thus, the convex portion shown in Fig. 3 can be used. The front end surface of 42 absorbs the substrate W by vacuum suction. As shown in Fig. 2, the polishing table 1 of the electrolytic composite polishing apparatus 250 is embedded with a film thickness such as a eddy current of a conductive film or the like on the surface of the substrate. The sensor coil 228 of the ITM 226 formed by the sensor. The signal output by the ITM 226 is input to the control unit 310, and the output of the control unit 310 is used to control the regulators RE3 to RE6. (polishing table, grinding 塾) Fig. 5A is a schematic view showing the importance of the electrolytic composite polishing apparatus. A longitudinal section of the polishing table 100. A disk-shaped support member 254 254 is fixed to the upper surface of the polishing table 100. The support member 254 is made of a conductive material (metal, alloy, conductive plastic, etc.). There is a polishing pad 101, and the upper surface of the polishing pad 101 serves as a polishing surface. The polishing table 1 is coupled to a rotating mechanism (not shown), whereby the polishing table 100 can be rotated integrally with the support member 254 and the polishing pad 101. The supply nozzle 102 extends in the radial direction of the polishing pad 1〇 1. The electrolyte supply nozzle 102 is provided with a supply port 10a of the electrolyte solution. The supply port 102a is located above the central portion of the polishing pad ιοί An electrolyte supply source (not shown) is supplied to the center portion of the polishing crucible 1G1 through the electrolyte supply nozzle 1 2 and 22 320663 200936309. When the polishing pad 1G1 rotates, the electrolyte is wetted outward and filled. The substrate head 1 and the polishing pad 101 are interposed between the plurality of through holes lG1 of the polishing crucible 1Q1. The supporting member 254 is connected to the negative electrode of the power source 252 and has a function of a first electrode (drag pole). The wiring and the supporting member (the electrical contact of the cathode 254 is a roller, a brush, etc. For example, if the 筮q A solid β- Α 所 所, the electrical contact 262 can be The support member 254 and the i-face are in contact with each other. The electrical contact 262 is preferably formed of a soft metal core having a smaller specific resistance such as gold, silver, mesh, platinum, etc. The side of the polishing pad 101 is disposed with a power source. The positive electrode connection 252 of 252 is adhered to an a-pole (° electric electrode or application point) 264. The substrate head 1 is such that the substrate W and the blade are exposed to the side of the polishing crucible 101 to bring the substrate W into contact with the grinding surface. The lower surface will be in contact with the second electrode 264. Power is supplied from the /electrode 264 to the substrate. In addition, power is supplied from the second electrode 264 to the substrate. Conductive film. Thus, the supporting member 254 is connected to the conductive film on the substrate w as an anode. °, the electrolyte in the through hole 101a of the honing 101 and the electrical connection I 5 5B diagram schematically shows the other weight 254 of the electrolytic composite polishing apparatus. It is too ΓΓ ΓΓ 底 底 复合 复合 复合 复合 复合 复合 复合 复合 复合A coffee cup and a cover member 254a covering the upper surface of the bottom member. As described above, as the cathode (the first lightning striker structure 4) has at least j, the cover member 254a and the bottom member 254b are formed of a conductive material. 320663 23 200936309 Support member 254 cover shame and grinding A plurality of communication holes 255 are formed at the same position of the through hole 101a of the 塾ι〇. Further, a plurality of communication grooves 256 that are in communication with the communication holes are formed on the lower surface of the cover member 254a. A communication groove is provided on the upper surface of the base member 254b. The center portion of the polishing crucible 101 is formed with a first electrolyte solution receiving port 258A1 penetrating vertically through the polishing pad 1 (1), and is connected to the first electrolyte solution at the lid member 254a. The second electrolyte receiving port 25 is formed at the same position of the port 258A. The second electrolyte receiving port 258B communicates with the plurality of communication grooves 256. By the configuration of the supply port from the electrolyte supply nozzle 1〇2 The electrolyte supplied from 102a flows through the first electrolyte receiving port 258A, the second electrolyte receiving port 258B, the communication groove 256, and the communication hole 255 to reach the through hole 101a. Then, in the through hole 1〇la Internal formation The electrolytic solution of the grinding surface flows upward to supply the electrolytic solution to the polishing surface. (First embodiment, electrolytic composite polishing method)._ Next, the electrolytic composite polishing method according to the first embodiment will be described. Description of the substrate before polishing. The film structure of the substrate W to be polished according to the present embodiment will be described. A so-called low dielectric value (Low) is formed on the surface of the substrate W formed of tantalum or the like. -k) an interlayer insulating film 62 made of an insulating material such as siCh, SiOF, SiOC, etc. The surface of the interlayer insulating film 62 is formed with a contact plug or a recess 63 for forming a wiring. The surface of the interlayer insulating film 62 is formed with a barrier film 64 made of titanium, coarse, tungsten, tantalum, and/or an alloy of such a metal having a thickness of about nm. The barrier film 64 320663 200936309 1 The metal material of the conductive film 66 to be described later is prevented from diffusing to the substrate W, or is provided to improve the adhesion between the conductive film 66 and the interlayer insulating film 62. The surface of the barrier film 64 is formed of tungsten having a thickness of about 500 to 600 nm. Place When the conductive film 66 is formed by electrolytic plating, a seed film (not shown) as an electrode for electrolytic plating is formed on the surface of the barrier film 64. The surface of the conductive film 66 is formed. A recess 67 having a height of about 300 nm and a width of about 100 /zm is formed in the same manner as the recess 63 of the interlayer insulating film 62. Alternatively, it may be made of aluminum, copper, silver, gold or an alloy of such metals other than tungsten. The conductive film 66 is formed of a metal material. Since only the conductive film 66 filled in the recess 63 of the interlayer insulating film 62 is used as a contact plug or a metal wiring, the conductive film 66 formed on the outer side of the recess 63 is not required. Therefore, the excess conductive film 66 is removed by electrolytic composite polishing. Fig. 6B is an explanatory view of electrolytic composite polishing. In the electrolytic composite polishing system, the electrolyte solution 50 is brought into contact with the conductive film on the surface of the substrate W, and a voltage is applied to the conductive film 66, and the surface of the substrate W is pressed against the polishing pad 101 while the substrate W and the polishing pad 101 are moved (rotated). The surface of the conductive film 66 is ground. Since a plurality of wirings are laminated via the interlayer insulating film, it is necessary to flatten the surface of the substrate W in a state where the excess conductive film 66 is removed. The electrolytic composite polishing is to form a protective film 70 formed of an electrically insulating substance on the surface of the conductive film 66 by applying a voltage to the conductive film 66. The protective film formed on the upper portion of the conductive film 66 (outside of the concave portion 67) is removed by the polishing pad 101. Therefore, the upper portion of the guide 25 320663 200936309 electric film 66 will dissolve in the electrolyte 50 and be removed. On the other hand, the conductive film of the lower portion L (inside of the concave portion 67) is shielded by the protective film 7〇 and is not dissolved in the electrolytic solution 50. By the above electrolytic composite grinding, the step of the conductive film is eliminated. Thereby, as shown in Fig. 6C, the surface of the conductive film 66 and the surface of the exposed barrier film 64 are placed on the same plane, and the substrate W is planarized. However, the tungsten polishing method by CMP has a grinding rate that is low because the acid slurry using pH < 4 is used to form a relatively thick tungsten oxide film, and then the mechanical mechanism of grinding is performed mechanically. Therefore, the electrolytic composite polishing method of the present embodiment employs an electrolytic solution of ρ Η 4 to 10 to form a different protection from the conventional tungsten oxide film. Here, an electrolyte having a pH in the range of 4 to 1 Torr is used at the beginning of the processing. However, due to the hydrogen generated during processing, the pH of the electrolyte may change after the start of processing. Therefore, the pH of the electrolyte is in the range of 4 to 10, at least before processing starts, processing. The pH at the end of the process or at the end of the processing will fall within the range of 4 to 10, and the pH will fall within this range at the time of substantial processing. The measurement of Qiu value was carried out using a pH measuring device D51S (handheld) manufactured by H〇RIBA, with temperature correction and a glass electrode method (JIS Form 1). The measurement was carried out at room temperature between 2 ° C and 30 ° C. Further, in the present embodiment, substantially any electrolytic solution can be used as long as it has an appropriate electrical conductivity (about lmS/cm). The main electrolyte contained in the electrolytic solution is not limited as long as it can provide an appropriate conductivity and does not cause the surface of the conductive film to become thick. Further, it is preferred to form a complex with tungsten or a chelate of 26 320663 200936309 and it is preferred to include, for example, an organic acid. The organic acid is composed of a salt of glycolic acid, pyrophyllin, phytic acid, citric acid, vermiculic acid, maleic acid, malonic acid, lactic acid, tartaric acid, calcined acid, and the like. It is preferred that any one or a plurality of the selected ones in the group be a pH of the complex pH or a chelate of the compound which is easy to form a scale. The electrolyte may also contain a pH simple component. p (4) can use alkali metal salts, alkaline earth metal salts, etc., but in order to prevent metal contamination, ammonium salts are preferred. The electrolyte may also contain an additive that generates an electrically insulating substance. Additives that generate electrical insulating materials can utilize primary amine polymers, such as allylamine polymers (polymers with side chains only having primary amine groups, molecular weights of 1,000 to 60,000), allylamine hydrochloride polymers (molecular weight of 1,000 to 60' 000), allylamine hydrochloride, salt-diallylamine hydrochloride copolymer (molecular weight · 20,000 to 1 〇〇, 〇〇〇), allylamine sulfamate polymer (molecular weight ❹I2, 000), alkene Propylamine-diallylamine acetate copolymer (molecular weight 100,000), allylamine-dimethylallylamine copolymer (molecular weight 丨, 〇〇〇), 邛 is methylcarbonylated allylamine polymer (molecular weight 15,000) ), a partially methylcarbonylated allylamine acetate polymer (molecular weight: 15,000), and the like. Further, the primary amine polymer may also be polyethyleneimine (molecular weight L _ to 70, _). The polyethylenimine-based molecule has an I-form of a branched k which contains a -, a secondary, a tertiary amine, and has an effect because it has a -amine in the molecule. The preferred concentration of the additive which will generate the electrically insulating substance is from 0.01 to 5% by weight in the case of polyethyleneimine, more preferably from 〇 to 1% by weight, 27 320663 200936309, and the concentration is less than 0.01% by weight. The current suppression effect (electrical insulation) is low. On the other hand, when the concentration is higher than 5% by weight, the increase in the current suppression effect with respect to the increase in the amount of addition tends to decrease, so that the concentration is not high. More than 5 wt% is necessary. By adding such an additive which generates an electrically insulating substance, the voltage range in which the step elimination is high can be shifted to a low position as will be described later. In the case of CMP, the concentration of the abrasive grains must be 1% or more. However, in the present embodiment, the concentration is preferably 1% or less. Although this surfactant can also be added to improve the dispersibility of the abrasive particles, since the concentration of the abrasive grains is originally low, there is no problem even if it is not added. An example of the above electrolyte solution is ammonium citrate (pH 8) used in the present embodiment. "The polishing rate of tungsten" was invented by the inventors of the present invention by the method described below. 加工 The processing experiment was carried out using an electrolytic polishing apparatus capable of processing only a portion of the substrate equivalent to a diameter of 40 mm. The electrode potential of the metal film formed on the substrate is processed by applying a voltage while rubbing the exposed metal film with a polishing pad adhered to the rotating polishing table. For example, the current rate of 1 mA/cm 2 can be obtained at a polishing rate of 50 to 150 nm/min. The electrode potential is measured using an electrochemical measurement system HZ_3 (manufactured by Hokuto Denko Co., Ltd.). The reference electrode system uses a silver/silver chloride electrode Ug/AgCl. The polishing pad is made of a foamed poly 320663 28 200936309 surface with a lattice-like groove on the surface (an IC1000 single-layer pad with a Χ-Υ groove, ΝΙΤΤΑ HAAS Co., Ltd.) Using this device, the anode polarization measurement was performed (the electrode potential of the substrate was gradually increased), and the relationship between the applied voltage and the current flowing through the substrate was measured. Fig. 7 is a graph showing the relationship between the potential of the conductive film and the current density. In Fig. 7, the vertical axis represents the current density, which indicates the current flowing per unit of the polished area on the substrate. Current density and grinding The higher the current density is, the more the amount of dissolution of the conductive film dissolved in the electrolyte becomes larger, and the faster the polishing rate. In addition, although the horizontal axis in Fig. 7 indicates the electrode potential, it is in the actual polishing apparatus. Controlling the electrode potential is troublesome, and therefore it is generally controlled by the applied voltage between the substrate to be polished and the cathode. Therefore, in the following description, the electrode power control of the substrate is expressed by the applied voltage. The applied voltage indicates the potential difference between the anode potential and the cathode including the electrode potential of the substrate as the anode and the electrode potential of the supporting member (grinding crucible) serving as the cathode. The electrolyte of pH 4 to 10 is brought into contact with the conductive film and then the applied voltage is "added, the current density changes rapidly at a predetermined electric charge. The applied voltage to the conductive film is increased from the enthalpy, and the current density is related to the voltage. Increasingly, but when the voltage exceeds the first change voltage of the first change point (such as point A) and continues to increase the voltage, the current density will decrease from increasing to increasing. Then when the voltage exceeds the second change point (for example, 8 When the second change voltage of the point) continues to increase the voltage, the degree of reduction of the current density is reduced, and then the current density is no longer reduced to become a substantially constant value. This phenomenon can be thought of as 320663 29 200936309 • Because the first application is applied When the voltage is lower than the voltage, a surface of the conductive film is formed with a protective film which is soluble for the electrolytic solution, and when a voltage equal to or higher than the second varying voltage is applied, the surface of the conductive film is insoluble to the electrolytic solution. The inventor of the present invention found that the first varying voltage and the second varying voltage described above will follow the substrate W and the polishing pad. The contact surface pressure changes. In Fig. 7, the thick line contact surface pressure is 0.5 psi (the contact surface pressure is a finite value, which corresponds to the honing of the upper portion of the step on the surface of the conductive film), and the thick broken line is The contact pressure is 0 psi (the contact pressure is 0, which is equivalent to the lower section of the surface of the conductive film). The first change point when the contact surface pressure is a finite value is point A, contact surface pressure When the finite value is the second change point is B point, the first change point when the contact surface pressure is 0 is C point, and the second change point when the contact surface pressure is 0 is D point (the threshold voltage). The higher the surface pressure, the larger the first and second changes in electric dust, and the higher the current density. The first change voltage (point C voltage) and the second change voltage (point D voltage) when the contact surface pressure is zero, The first change voltage (point A voltage) and the second change voltage (point B voltage) are lower than about 0.5 V when the contact surface pressure is a finite value. Here, the applied voltage is in the range of 0 to C point voltage. For (2 areas, the voltage from point C to point B is in the range of β, and the range above the voltage at point B is 7 areas. The application voltage is in the range of the voltage from the point C to the voltage at the point C. The eighth embodiment is an explanatory diagram of the formation state of the protective film when the voltage of each of the regions is applied to the conductive film, and the eighth embodiment is the alpha region. In the case, the case of the 8th picture is the cold area, and the case of the 8C picture 7 area. 30 320663 200936309 When the voltage of the α area is applied, as shown in Fig. 8A = 2, the capacitive protective medium 71. In the case where the surface of the polishing crucible 101 and the conductive film 66 has an upper portion Η, the protective film 71 is ground and completely = when a voltage of the r region is applied for a finite value, as shown in FIG. 8C, the liquid is discharged. 50 is an insoluble protective film? 2. In the formation of the guide for electricity

In the case of a difference, in the case where the 1α1 and the conductive (4) are connected to the (10) surface portion L, the protective film 72 is not left to be polished and/or underneath. The state between the two is shown. That is, in the polishing pad 1〇1 and the “:= contact surface pressure is a finite value above the segment 1!, a solubility protective film is formed, and the protective film is removed by grinding. In the polishing 塾m and the conductive film (10) When the junction pressure is 0, the in-situ portion L forms an insoluble protective film 72, and this 72· remains without being polished. 5. In this embodiment, the applied voltage is maintained in the 0 region, and electrolytic composite polishing is performed. In the upper portion, the conductive film 66 is promoted to dissolve in the electrolytic solution, and the lower portion L suppresses dissolution of the conductive film 66 into the electrolytic solution. Therefore, the step difference of the surface of the conductive film 66 can be quickly eliminated. In the case of the voltage, since the polishing speed of the lower portion 1 covered under the protective film 72 is relatively slow, it is difficult to cause dishing of the conductive film 66. In addition, since the pressure can be adjusted to control the upper portion Since the polishing rate is set, the contact surface pressure between the polishing 塾1 〇1 and the conductive film 66 is set lower, and the grinding residue can be suppressed. For example, the conventional embodiment can be used for the contact surface of 4 psi in the conventional CMP. Pressure, 320663 200 936309 * Set at 2 Psi. In addition, the contact surface pressure is the force that presses the substrate head against the rotating platform (also known as the platen) divided by the area of the wafer that is in contact with the polishing pad, ie the contact area. The value obtained by the value. At this time, the area occupied by the through hole penetrating the polishing pad is subtracted from the contact area. As described above, the current density and the polishing rate have a relationship that the current density is higher and the polishing rate is faster. As shown in Figure 7, the voltage is applied to the 〇: region of the voltage at point c, and the contact surface pressure is finite (〇·5 psi) and the contact surface pressure is 〇(〇❿ psi). The density will increase with the increase of the voltage. In contrast, the voltage at point C is increased to the voltage at point A (in the 5 region, the current density at the contact surface pressure is increased, but the contact surface pressure is increased. At this time, the current density will decrease. Therefore, the difference in current density when the contact surface pressure is finite in the <5 region and the contact surface pressure is 0 is usually smaller than the difference in current density in the α region. △ I a is large. When the contact surface pressure is finite, The difference in current density when the contact pressure is 0 is actually the difference in the polishing speed of the upper portion and the lower portion corresponding to the step difference of the surface of the conductive film. Therefore, the applied voltage is maintained in the region of 5, and the surface of the conductive film is polished. The difference between the polishing speeds of the upper and lower sections of the step becomes larger, so that the step of the surface of the conductive film can be quickly eliminated. The thick line in 帛7® indicates that the electrolytic shirt contains the slaves that generate electrical insulating substances; The condition of '] is not added to the fine line table by adding 1% by weight of polyethyleneimine (as shown) as the addition of electrical insulating material f. In addition, the contact pressure of the solid line to the substrate is 0.5 psi. In the case of a dotted line, the contact pressure is 0 psi. 320663 32 200936309 * It is known that the current density does not increase when the additive (or the concentration is very low) which generates an electrically insulating substance is not contained. The reason for this is conceivable because the higher the concentration of the additive which generates the electrically insulating substance, the stronger the protective film is formed, and it is difficult to remove the protective film by polishing. Therefore, when it is desired to increase the polishing rate, it is sufficient to use an electrolyte having a low concentration of an additive which generates an electrically insulating substance. On the other hand, in order to reduce the polishing rate in order to perform polishing of the thin conductive film or to stop the correct polishing, an electrolyte having a high concentration of an additive which generates an electrically insulating substance can be used. Further, it can be seen from Fig. 7 that the first and second varying voltages become high when the additive (or the concentration is low) which generates an electrically insulating substance is not contained. Therefore, it is preferable to adjust the applied voltage in accordance with the sensitivity of the additive which generates the electrically insulating substance. Fig. 9 is a graph showing the relationship between the applied voltage and the current density when the pH of the electrolytic solution is changed. The experiment in Figure 9 uses an electrolyte of pH 4, pH 6, pH 8, pH 9 (no additives that will generate electrical insulating materials). ❾ It is known that the higher the pH of the electrolyte, the higher the current density. The reason for this is because the higher the pH of the electrolyte, the more the dissolution of the conductive film is promoted. Therefore, when it is desired to increase the polishing rate, an electrolyte having a large pH can be used. Conversely, when it is desired to reduce the polishing rate, an electrolyte having a small pH can be used. Further, it can be seen from Fig. 9 that the higher the pH of the electrolyte, the higher the first and second varying voltages. Therefore, it is preferable to adjust the applied voltage depending on the pH of the electrolyte. Fig. 10 is a graph showing the relationship between the applied voltage and the current density when the rotational speed of the polishing pad is changed. The experiment in the figure uses an electrolyte that does not contain an additive that will generate an electrically insulating substance. In Fig. 10, the thick line is 320663 33 200936309 ' when the rotation speed is 250 rpm, and the thin line speed is 50 rpm. Further, the solid-line polishing pad has a contact surface pressure of 〇5 psi with the substrate, and the dotted line has a contact surface pressure of 〇 psi. It is known that the higher the rotational speed of the polishing pad, the higher the current density. The reason for this is considered to be that the higher the rotational speed of the polishing pad, the faster the removal of the protective film is, and the dissolution of the conductive film is promoted. Therefore, it is desirable to increase the rotational speed of the polishing pad when the polishing speed is increased. Conversely, when it is desired to reduce the polishing speed, the rotational speed of the polishing pad can be lowered. The rotational speed of the polishing pad can also be varied by changing during the grinding process. Further, it can be seen from the first diagram that the higher the rotational speed of the polishing pad, the higher the first and second varying voltages. Therefore, it is preferable to adjust the applied voltage in accordance with the rotational speed of the polishing pad. (Second embodiment, electrolytic composite polishing method) Next, the electrolytic composite polishing method according to the second embodiment will be described. In the first embodiment, the polishing process is performed while maintaining the applied voltage of the conductive film in a predetermined range. On the other hand, the second embodiment differs from the first embodiment in that a protective film forming step of applying a predetermined voltage to the conductive film to form a protective film is performed before the polishing step. Hereinafter, a detailed description of the configuration of the first embodiment and the first embodiment will be omitted. First, a protective film forming step of bringing an electrolytic solution into contact with a conductive film on the surface of the substrate and applying a voltage to the conductive film to form a protective film on the surface of the conductive film is performed. Here, a voltage equal to or higher than the second variation voltage of the second change point (e.g., point D in Fig. 7) when the contact surface pressure is 〇 is applied. Thereby, it is conceivable that a protective film 72 which is 34 320663 200936309 'insoluble to the electrolytic solution 50 is formed as shown in Fig. 8C. This protective film 72 is formed on the entire surface of the electroconductive film 66 and is not <inverse, and does not change even if the applied voltage is lowered to the second variation voltage. After this protective film forming step, a usual electrolytic composite polishing step is performed. As a result, the protective film 72 formed on the upper portion U of the conductive film 66 is polished and removed, but the protective film 72 formed on the lower portion L of the conductive film 66 is not left by polishing. Thereby, the upper portion η promotes dissolution of the conductive film 66 into the electrolytic solution, and in the lower portion 1 suppresses dissolution of the conductive film © 66 into the electrolytic solution. Therefore, the step difference of the surface of the conductive film 66 can be quickly eliminated. (Modification) A chemical mechanical polishing (CMP) step may be performed after the above-described protective film forming step. Fig. 11 is a schematic view of a CMP apparatus. Μ 系 系 系 系 系 系 系 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 一边 , 一边 , And the surface of the conductive film is polished. Even if the process is performed after the protective film forming step, the protective film 72 formed on the upper portion of the conductive film 66 as shown in FIG. 8C is polished and removed, but is formed on the conductive film 66. The protective layer 72 of the lower portion L is not left to be ground by grinding. Thereby, the conductive film 66 is promoted to dissolve in the electrolytic solution in the upper portion, and the conductive film 66 is prevented from being dissolved in the electrolytic solution in the lower portion L. Therefore, the step difference of the surface of the conductive film 66 can be quickly eliminated. In addition, the technical scope of the present invention is not limited to the above-described embodiment 320663 35 200936309, but includes various modifications in addition to the above-described embodiments and the like without departing from the scope of the present invention. Change. That is, the specific materials, configurations, and the like given in the embodiments and the like are merely examples, and appropriate changes can be made. (Polishing pad) In addition, the following things can also be used as a polishing pad. Regarding the type of the abrasive mash, there are, for example, a separate foamed polyurethane pad and a continuous hair suede pad. In the case of using electrolysis without abrasive particles, a fixed abrasive pad made by bonding the abrasive particles to each other by using a binder may be used. The above abrasive grains may be: cerium oxide (Ce〇2), aluminum oxide (a12〇3), cerium carbide (SiC), cerium oxide (Si〇2), zirconia (Zr〇2), iron oxide (Fe〇, Fe2〇3, Fe3〇4), manganese oxide (Mn〇2, Mm〇3), magnesium oxide (Mg〇), oxidation #5 (Ca0), barium oxide (BaO), zinc oxide (Zn〇), barium carbonate (Bac〇3), calcium carbonate (CaC〇3), diamond (C), or a composite of the above materials. In addition, the bonding agent can be: phenol resin, amine-based plastic resin (amin〇plast 10resin), urethane resin, epoxy resin, acrylic resin, acrylated isocyanuric resin, urea-furfural resin, different A polycyanate resin, an acrylated amine phthalate resin, an acrylated epoxy resin, or the like. Further, in order to secure the power supply to the surface of the conductive film to be polished, a conductive pad having a conductive surface on at least a part of the polishing surface may be used. Here, regarding the groove shape of the polishing pad, one or more (1) concentric circular grooves, (2) eccentric grooves, (3) polygonal grooves (including lattice grooves), and (4) spirals may be formed. a groove, (5) a radiation groove, (6) a parallel groove, (7) an arc groove, or a combination of such grooves. These groove shapes affect the electrolysis 320663 36 200936309 μ## 'the heart si groove and the eccentric groove have the effect of holding the electrolyte on the polishing pad because the vertical flow path is closed. On the other hand, the polygonal groove and the radiation groove have a function of promoting the flow of the electrolyte to the object to be polished and discharged to the outside of the polishing pad, in order to increase the flow of the electrolyte into the surface to be processed of the substrate, from the processed surface of the substrate. The efficiency of the inner flow and the retention in the machined surface of the substrate can also be adjusted by appropriately adjusting the groove width, the groove pitch, and the groove depth in the polishing face to adjust the groove density distribution in the polishing pad. For example, the groove width and the groove depth may be 〇, 4 mm or more, and the groove pitch is more than twice the groove width. If the flow of the electrolyte is considered, the groove width and the groove depth are 〇. The above is preferred. In addition, in order to activate the electrolyte (four) movement between the grooves, a (four) (four) groove may be provided between the dragons (for example, a plurality of fine grooves formed between the concentric grooves, a fine groove formed between the coarse lattice grooves, etc.) . Further, regarding the sectional shape of the Lay, a quadrangular groove, a circular groove, and a V-shaped groove may be employed. Further, in order to promote the discharge of the electrolyte from the groove, the direction of rotation of the polishing table to which the polishing pad is mounted may be considered, and the shape f may be inclined toward the downstream direction in the direction of rotation. On the other hand, in order to suppress the electrolyte = when the groove is discharged, the reverse groove which is inclined toward the upstream side in the rotational direction can be formed. Further, in order to maintain the electrolyte, one or more through holes may be formed in the surface of the polishing pad. In addition, the shape of the contact surface of the polishing pad with the wafer affects the mechanical action of removing the protective film formed by electrolysis. In order to increase the contact surface = the machine used, the shape of the contact surface can be sharp, for example, 'conical, polygonal, pyramidal, 稜鏡-shaped, etc. Here, 320663 37 200936309 • Depending on the object to be polished, if the shape of the contact surface is too sharp, it may cause a mark or the like. The method to avoid this is to form the shape of the contact surface into, for example, a truncated cone or a truncated cone. The shape that is flattened above the class. Further, the shape which makes the mechanical action generated by the contact surface more reduced' is exemplified by a cylindrical shape, an elliptical cylindrical shape, a hemispherical shape, and the like. The configuration of these shapes may be in the form of a regularity such as a lattice, a zigzag, a triangular configuration, or may be configured in any form in order to eliminate the regularity. Further, these shapes may be plural or more in the polishing surface of the polishing pad, and the density distribution thereof may be adjusted. ❹ (Thickness Detecting Sensor) Although the eddy current sensor is used as an example of a method of detecting the residual film thickness of the conductive raft as shown in the embodiment of Fig. 2, an optical type may be used. Monitor, fluorescent X-ray film thickness measurement, voltage-current change detection, etc. - The optical monitor is monitored by a phenomenon in which the intensity of the reflected light changes due to light interference, so that the method of irradiating the measurement light from the light source embedded in the polishing table through the hole of the polishing pad or the substrate can be used The method of measuring the state of the protrusion® outside the polishing table. Further, since the starting point of the change differs depending on the wavelength of the light used, the wavelength is appropriately selected for the material to be polished. The measurement of the thickness of the fluorescent X-ray film is performed by the phenomenon that the intensity of the fluorescent X-ray generated when the X-ray is irradiated once to the measurement target changes depending on the thickness of the film, so that it is buried in the polishing table during polishing. The X-ray source inside is measured by irradiating the conductive film with X-rays once. The voltage-current change detection method uses a phenomenon in which the resistance changes depending on the film thickness of the conductive film of the measurement object 320663 38 200936309. This is a method of calculating the film thickness from the electric resistance by measuring the change in the current by making the voltage constant or by measuring the change in the voltage while the current is constant. According to this method, the film thickness can be detected by monitoring the voltage and current of the grinding order, so that it can be easily used. Further, a method of detecting the state (10) of the polishing of the conductive film in the polishing of the conductive film on the resistive film or the polishing of the conductive film including the barrier film on the insulating film, in addition to the method of detecting the state in which the conductive film has been polished (10) In addition to the above-mentioned method, there are, for example, a method of monitoring the change in the surface temperature of the polishing crucible or the surface temperature of the substrate, a method of monitoring the change in the friction between the substrate and the polishing pad, and monitoring the change of the surface image. A method of monitoring a change in a component (a concentration of an oxide of a by-product, an ion concentration derived from a conductive film) in a polishing apparatus or an electrolytic solution, or the like. The method of monitoring the change of the surface temperature of the polishing pad or the surface temperature of the substrate may be: measuring the surface temperature of the polishing crucible by the radiation temperature, or measuring the substrate through the hole provided in the polishing pad by a radiation thermometer embedded in the crucible polishing table. The method of the temperature of the surface. The method of monitoring the change of the friction between the substrate and the polishing pad may be performed by using a variation of the driving current of the polishing table or the substrate holder on which the polishing pad is mounted, or measuring the vibration amplitude of the specific frequency with respect to the substrate holder over time. The method of change. The method for monitoring the change of the image on the surface of the substrate may be: measuring the change of the hue of the surface of the substrate by the chromaticity sensor embedded in the polishing table through the hole provided in the polishing pad, or measuring the surface of the substrate obtained by using the CCD. Dimension 39 320663 200936309 Method of change of imagery. A method of monitoring a change in a component (a concentration of an oxide of a by-product, and an ionity of a source derived from a conductive film) in a slurry or an electrolyte may be obtained by measuring a slurry discharged from a polishing table A method of changing the ion concentration of a conductive film. According to the present invention, in the case where there is a step on the surface of the conductive crucible, a protective film is formed in a portion above the finite value of the contact surface of the electroconductive film and the polishing pad, and the protective film is completely removed by grinding. In addition, in the conductive film and the surface of the polishing pad (4) G, the axis is insoluble in the protective film, and the protective film is not left to be polished. Thereby, in the upper stage, the conductive film is dissolved in the electrolytic solution, and the dissolution of the conductive film is suppressed in the lower portion. Therefore, the step difference of the surface of the conductive film can be quickly eliminated. ★ Next, the present invention will be described with reference to the drawings: a third embodiment. (Second Embodiment) (Substrate Processing Apparatus) The configuration of the substrate processing apparatus will be omitted from the description of the common phase of the first embodiment (5). As explained in the embodiment of the rigid face, in Fig. 2, the pressures inside the pressure chambers 21 to 25 can be independently changed by the freezer RE2 to RE6, so that the respective portions of the substrate w can be targeted. (Divided area) Adjusts the pressing force of the substrate w to the polishing crucible by the elastic 塾 (the contact surface pressure acting on the surface of the substrate). To change the tongue, as shown in Fig. 4, the pressure of each of the pressure chambers 21 to 25 is adjusted during the grinding to adjust the pressing force of the buckle 3 against the polishing crucible 101, and the substrate W is pressed to the pressing force of the polishing pad iQi. The central portion of the substrate 40 40 320663 200936309 (Fig. 4 c), and from the central portion to the intermediate portion (C2), the peripheral portion (C3), then the peripheral portion (C4), and then to the substrate w The distribution of the polishing pressure (contact surface pressure acting on the substrate surface) of each portion such as the outer peripheral portion of the outer buckle 3 is set to a desired value. Thus, the substrate W can be divided into four concentric circles and ring portions (C1 to C4)' and each portion can be pressed with an independent pressing force. Although the polishing speed is related to the pressing force of the surface to be polished of the substrate #, since the pressing force of each portion can be controlled as described above, the four portions (C1 to C4) of the base plate W can be independently controlled. Grinding speed. Therefore, even if the film thickness of the film to be honed on the surface of the substrate is unevenly distributed in the radial direction, the entire surface of the substrate W can be prevented from being insufficiently polished or excessively polished. That is, even if the film thickness of the film to be polished on the surface of the substrate w is different depending on the position in the radial direction of the substrate W, it is only necessary to make the substrate of each of the pressure chambers 21 to 25 located above The film thickness of the surface is higher than the pressure above the thick portion (4), the other pressure is high, or the pressure of the pressure chamber above the thin portion of the surface of the substrate W is lower than that of the other pressure chambers. The pressing speed of the portion to be polished on the thicker portion of the film thickness is greater than the pressing force on the surface to be polished having a thinner portion of the film thickness, so that the polishing rate of the portion can be selectively increased. Thereby, regardless of the film thickness distribution at the time of film formation, the entire surface of the polishing substrate W can be polished without excessive and insufficient. Further, in the polishing table of the present embodiment, a power supply electrode (applied to 320663 41 200936309) 264 connected to the positive electrode of the power source 252 is disposed at a position on the side of the polishing pad 1〇1. In the substrate head 1, the substrate W is brought into contact with the polishing surface in a state where a part of the substrate W is exposed on the side of the polishing pad 101, and the peripheral portion C4 of the lower surface of the substrate W is brought into contact with the feeding electrode 264. Thereby, the conductive film 66 is applied from the donor electrode 264 to the substrate W. Further, the conductive film 66 of the substrate w may be applied from the power supply electrode 264 through the buckle. Then, the support member 254 as the cathode and the conductive film on the substrate w as the anode are electrically connected by the electrolytic solution filled in the through holes 10a of the polishing pad 101. (electrolytic composite grinding method)

Next, the electrolytic composite polishing method of the present embodiment will be described. In the electrolytic composite polishing method of the present embodiment, the description of the portions common to the electrolytic composite polishing method of the first embodiment will be omitted. Figures 12A to 12C are explanatory views of electrolytic composite grinding. In the figures 1 to 12C, the conductive film 66 as the surface to be polished is disposed downward. First, as shown in Fig. 12A, while the electrolyte solution 5 is brought into contact with the conductive film on the surface of the substrate and a voltage is applied to the conductive film 66, the surface of the substrate is pressed against the polishing pad 1〇1 while the substrate is being formed. It is opposite to the polishing pad 1〇1 (rotational movement, and the surface of the conductive film 66 is polished. Since a plurality of wirings are formed by laminating the interlayer insulating film 6 2, it is necessary to remove the excess conductive film 66 in a state of being removed. The surface of the substrate W is flat: L·Chemical de-composite polishing is to form a protective film formed of an electrically insulating substance on the surface of the conductive film 66 by applying a house to the conductive film (10). The upper portion of the conductive film 66 is formed. The protective film of the crucible (the outer side of the concave portion 67) is removed by the contact with the polishing crucible 101. Therefore, the conductive film 66 of the upper portion is dissolved in the electrolytic solution 5, and is removed. In contrast, the lower portion 320663 42 200936309 The conductive film of the portion L (inside of the concave portion 67) is shielded by the protective film and is not dissolved in the electrolytic solution 50. By the above electrolytic composite polishing, the step of the conductive film is eliminated. Thereby, the conductive film 66 is made The surface is disposed on the same plane as the surface of the exposed barrier film 64, and the substrate W is planarized. Here, the inventors of the present invention have found that adjusting the potential of each portion of the surface of the substrate W can control the polishing of each portion of the substrate W. speed. In other words, there is a difference in resistance between the metal film formed on the surface of the substrate W, that is, the barrier film 64 of the lower layer shown in FIG. 12A and the conductive film 66 of the upper layer, and the difference between the portions of the substrate W is adjusted by using the difference. When a voltage is applied from the power supply electrode 264 provided on the surface of the metal film to the peripheral portion C4 of the substrate W, and the conductive film 66 remains in the entire surface of the substrate W, the entire substrate will have substantially equal voltages. However, When the conductive film 66 is removed to expose a portion of the barrier film 64 (for example, in the vicinity of the power supply electrode 264) as shown in Fig. 12B, the voltage distribution of the surface of the substrate W changes. Specifically, the periphery of the substrate W is made. In the region other than the peripheral portion C4 of the substrate W after the barrier film 64 in the portion C4 is exposed, the region of the center C1 to C3 of the substrate w remains as the conductive film 66 having a smaller resistance than the barrier film μ. The resist film 64 is applied to the remaining conductive film 66. Therefore, the voltage applied to the conductive film 66 is lowered depending on the distance from the power supply electrode 264. In this embodiment, as shown in FIG. 12B, the substrate is first introduced. Conductive film 66 on w Partial removal causes the barrier film 64 to be exposed. Specifically, the 5' system side controls the flow rate of the pressurized fluid supplied to the pressure chambers 22 to 25 of the substrate head 1 (refer to FIG. 3) so that the substrate w and the polishing 6631〇1 is connected to 320663 43 200936309 The contact surface is pressed to the highest edge portion C4 (see Fig. 4) of the substrate W, and is polished. The distribution of the contact surface pressure other than the peripheral edge portion C4 of the substrate W is set. It is preferable that the distribution gradually decreases from the outer peripheral portion C3 of the substrate W to the central portion C1 (see FIG. 4), but the contact surface pressure from the central portion C1 of the substrate W to the outer peripheral portion C3 is set to be equal. When the polishing is performed in such a manner as to contact the surface pressure, the conductive film is removed first in the region of the peripheral portion C4 of the substrate, that is, in the region near the feeding electrode 264. Then, the barrier film 64 in the region of the peripheral portion C4 of the substrate W is exposed. At this time, in the region other than the region of the substrate W and the edge portion C4, that is, the region from the peripheral portion C3 of the substrate W to the central portion C1, the conductive film 66 remains. In particular, when the distribution of the contact surface pressure of the substrate W is set to gradually decrease from the outer peripheral portion C3 to the central portion C1, the residual film thickness of the conductive film 66 is formed to be thicker from the outer peripheral portion C3 toward the central portion C1. form. Further, the method of removing a portion of the conductive film 66 on the substrate W to expose the barrier film 64 is further divided into a plurality of small cathodes (small electrodes) which are opposed to the substrate w (opposing electrode) A method of dividing a cathode (dividing electrode) is used. An example of such a divided cathode is a plurality of cathodes K1 to K3 which are divided into concentric circles with respect to the center of the polishing table as shown in Fig. 13. The voltage applied between the cathode of the outermost periphery (the cathode of Fig. 13 and the substrate) is lower than the voltage of the first change point a shown in Fig. 7, and the voltage of K2 is higher than that of the other cathodes When it is high, the polishing speed 32062 44 200936309 of the peripheral portion C4 of the substrate w having the longest (highest frequency) direction with respect to the cathode K3 is the fastest, and the conductive film 66 in this region is removed first. The divided cathode performs voltage control such that the applied voltage gradually decreases from the outermost peripheral cathode K3 to the central cathode K1 (the cathode K3 > cathode K2 > cathode K1 as seen in Fig. 13), because the grinding The remaining film thickness of the conductive film 66 is made thicker from the outer peripheral portion C3 of the substrate W toward the central portion C1, and the barrier film 64 is gradually exposed from the peripheral edge portion C4 of the substrate W. Therefore, it is a good method. After the film 64 is exposed, the ❿ distribution of the contact surface pressure acting on the substrate W is reversed. Specifically, the contact surface pressure acting on the peripheral edge portion C4 of the substrate W is set to be small or not in contact with each other. Acting on the peripheral portion C3 of the substrate w to the middle The contact surface pressure of the core portion C1 is large. Alternatively, the contact surface pressure of the entire surface can be made uniform. Thereby, it is possible to surely prevent the abrasion caused by the mechanical polishing action on the peripheral portion of the substrate W exposed by the barrier film 64. In addition, in the electrolytic composite polishing of the present embodiment, polishing is performed while measuring the residual film thickness of the conductive film 66 by a film thickness detector. The film thickness sensor preferably uses an eddy current sensor vortex. The current sensor detects the film thickness by a phenomenon in which the combined impedance changes depending on the film thickness of each portion, and is measured by applying a high frequency to the conductive film from an eddy current sensor embedded in the polishing table 100. Therefore, even a film having a thick film thickness of the conductive film 66 can be subjected to high-accuracy film thickness measurement. Here, the barrier film 64 in the peripheral portion C4 region of the substrate W is exposed, and the substrate is exposed. When the voltage distribution of W changes, the electric power applied to the power supply electrode 264 is increased. Specifically, the area of the peripheral portion c4 of the substrate is set to 320663 45 w ❹ ❿ 200936309 The voltage of the domain is equal to or higher than the C point voltage. And points C and D in Figure 7 The thunder of the electric house, and the above-mentioned electric house (the area to be inspected (the C4 area of the substrate W is exposed, so even the peripheral portion of the substrate W) is further polished. 66, it is not easy to The surface is formed with a dish-shaped recess Y having a conductive film for wiring. On the surface of the barrier film 64, the central portion α of the plate w to the base of the outer conductive film 66 is fixed to the voltage P C3 '. Since the barrier film 4 is applied, the electric disk of the peripheral portion C4 region of the electric resistance is prevented, and the inter-substrate substrate can prevent the remaining portion of the conductive film 66, the portion C1, and the peripheral portion C3 region. Central current density state. Specifically, in the case where M_士1 is only in the center portion 5 and is formed in the central portion of the substrate W, the voltage in the peripheral portion C3 is below the voltage at the point 7 of Fig. 7, preferably "electricity". In the following, it is more preferable to be the voltage in the d region. Thereby, the region around the peripheral portion C4 of the substrate W flows, for example, the current in the vicinity of the first varying voltage (voltage at point D in FIG. 7) when the contact surface is 0. In the central portion C1 to c3 of the 'substrate W, a current near the first varying voltage (for example, the voltage at point a in FIG. 7) flows. In other words, the region where the barrier film 64 is exposed (the peripheral portion of the substrate w is The region is not subjected to further polishing, and the polishing is promoted in the central portions C1 to C3 of the substrate f. As a result, as shown in Fig. 12C, the conductive film in the region other than the concave portion 63 on the surface of the substrate w is removed. In the present embodiment as described above, since the voltage of the exposed region of the barrier film 64 exceeds the threshold voltage, the current density is decreased by '46 320663 200936309 :; == the grinding speed is lowered. Even if the resistance of the resist _ plug or wiring is present : It is also difficult to form a polishing solution on the surface of the conductive film 66, so that it is not necessary to use a conventional slurry: the ratio of the mechanical polishing action is lowered, and the ratio of the mechanical polishing action is lowered. In the exposed area of the barrier film 64, the contact surface pressure of the polishing crucible becomes low, so the ratio of the mechanical polishing action is lowered, and dishing and abrasion can be prevented. F secret 2: * Resistive film having a smaller resistance than the barrier film 64 The remaining 2 domain 'voltage will drop due to the potential drop in the exposed portion of the barrier film 64 = '= _ current dense resistance _64 (four) (four) domain high state. Therefore, in the region where the conductive film 66 remains, the grinding =: scratch If the damage and the dishing are smooth, the basin will be replaced by the contact surface pressure ratio of the region near the feeding electrode 264 = the contact surface of the region is high, so that the region f near the feeding electrode is compared with the other The area is more promoted, so the first = 臈 66 is removed. Therefore, after the barrier 骐 64 is exposed, the voltage applied to the metal _ can be obtained at the power supply electrode, and the voltage is gradually lowered with the voltage of : Distribution. Therefore, it is possible to make the barrier film In the step of the horse voltage, the remaining conductive film (10) is accurately placed. In the seventh figure, the thick-line electrolyte does not contain a graph showing the case where electrical insulation is generated (4) 320663 47 200936309 • The thin line indicates that polyethylene is added. The weight of the imiline is used as an additive which generates an electrically insulating substance. In addition, the contact pressure of the solid line between the polishing pad and the substrate is 0.5 psi, and the line pressure of the broken line is 0 psi. In the case where the additive (or the concentration is low) which generates an electrically insulating substance is not contained, the current density becomes high. The reason is conceivable because the higher the concentration of the additive which generates the electrically insulating substance, the stronger the stronger. The film is protected and it is difficult to remove it by honing. Therefore, when it is desired to increase the honing speed, an electrolyte having a low concentration of an additive which generates an electrically insulating substance can be used. On the other hand, in order to reduce the polishing rate in order to polish the thin conductive film or to stop the correct polishing, an electrolyte having a high concentration of an additive which generates an electrically insulating substance can be used. Further, it can be seen from Fig. 7. The first and second varying voltages become high without containing an additive (or a low concentration) which generates an electrically insulating substance. Therefore, it is preferable to adjust the applied voltage in accordance with the concentration of the additive which generates the electrically insulating substance. Further, the technical scope of the present invention is not limited to the above-described embodiments and modifications thereof, but includes various modifications in addition to the above-described embodiments and the like without departing from the scope of the present invention. . That is, the specific materials, configurations, and the like given in the embodiments and the like are merely examples, and appropriate changes can be made. For example, in the present embodiment, the configuration in which the feeding electrode is provided only at one of the peripheral portions of the substrate has been described. However, the feeding electrode may be provided in plural places on the substrate. Thereby, the contact area for voltage application is increased, and the contact resistance can be cut, so that the substrate can be correctly supplied to the substrate 320663 48 200936309. In this case, each of the feeding electrodes is preferably provided in a concentric shape of the substrate. Further, although the configuration for increasing the voltage after the barrier film is exposed has been described, the film thickness sensor can be used to detect the time before the barrier film is exposed, and the voltage is raised from that point in time. (Polishing pad) The material, shape and the like of the polishing pad are the same as those of the second embodiment, and the description thereof will be omitted. (Fourth embodiment) Next, a fourth embodiment of the electrolytic composite polishing method of the present invention will be described. In the present embodiment, the same reference numerals are given to the same components as those in the second embodiment, and the description thereof will be omitted. The position of the power supply electrode 264 can also be fixed, and the voltage of the exposed region of the barrier film 64 and the residual region of the conductive film 66 can be controlled by moving the position of the substrate head j. Q The applied voltage is slightly above the point D of Fig. 7 (〇5v), and the feeding electrode 264 (applying point) is placed very close to the outer circumference of the grinding station 1 00 (within 1 〇 coffee) . Further, at the initial stage of polishing, polishing is performed in a state in which only the outermost periphery of the substrate W is suspended, and then the substrate head j gradually moves away from the center of the polishing table 2 at the stage where the second barrier film 64 is exposed, that is, toward Move in the direction of increasing the amount of suspension. The voltage of the electrode 264 is in direct contact with the exposed portion of the barrier film 64, and the position (4) of the etched L is still remaining. Further, according to the present embodiment as described above, in the stage where the barrier film 64 is exposed 320663 49 200936309 'the substrate head 1 is gradually moved away from the center of the honing table 100, the barrier film 64 can be exposed. The voltage of the region is maintained at a high voltage state. By the fact that even in the exposed region of the barrier film 64, there is a case where the conductive film 66 which becomes a contact plug or wiring exists, it is difficult to form a dish-shaped recess on the surface of the conductive crucible 66. Further, after the substrate head 1 is moved, the voltage applied to the power supply electrode 264 may be increased until the voltage at which the barrier film 64 is exposed reaches a threshold voltage (voltage C at the seventh point). The composition. According to this configuration, even if the voltage is not largely increased, the voltage in the region where the barrier film 64 is exposed can be surely brought to a threshold voltage or higher. Thereby, even if the exposed region of the barrier film 64 has the electric film 66 to be a contact plug or a wiring, it is difficult to form the surface of the conductive film 66, and the barrier film 64 can be surely prevented from being exposed. The area is affected by the grinding. Therefore, in the remaining region of the conductive film 66, the polishing may not be performed in the region where the barrier film is exposed, and in the case of the damage of the conductive film 66 and the dish shape (4), the contact is quickly contacted, and the power supply electrode is provided. 264 and almost all of the material 264 of the substrate w, and a soft material such as a daily carbon resin is used as the power feeding electrode, etc. I: the base-=== spin-milling station (10) is not necessarily located at The structure is close to the electric electrode configuration. For example, it is also possible to make the electric heart 5 in the grinding crucible 4. In this case, even if the substrate is relieved by 320663 50 200936309, the substrate w can be polished without being overhanged. The power supply electrode 264 is disposed on the outer periphery of the polishing table 1〇〇. Although the case where the distance is within 10 mm is described, a concentric circular conductive crucible having a width of, for example, about 1 cm may be embedded in the polishing crucible 4 as another embodiment of the feeding electrode. When the conductive pad is disposed at a position larger than the outer circumference of the polishing table 101 by a distance larger than the radius of the substrate W, even if the conductive pad reaches the center of the substrate, the substrate W can be stably ground without being suspended. According to the present invention, the voltage of the exposed region of the under film is set to exceed the threshold voltage, whereby it is difficult to use the conductive film to be a contact plug or a wiring even in the exposed region of the under film. The surface of the conductive film forms a dishing recess. Further, since the polishing is performed by the electrochemical dissolution action, it is not necessary to use a polishing slurry having a high abrasive grain concentration as in the related art, and it is not necessary to perform polishing with a high contact surface pressure, so that the ratio of the mechanical polishing action is lowered, and the grinding money can be prevented. It happened. On the other hand, in a region where the electric resistance of the conductive film smaller than the base film remains, the voltage is set to exceed the threshold voltage and is lower than the maximum voltage, thereby planarizing the region to the same level as the base film. The high current density state was maintained before. Therefore, even if there is a conductive film to be a contact plug or a wiring, the polishing is continued, so that the conductive film can be quickly removed and flattened while suppressing damage such as scratches and dishing. . The preferred embodiments of the present invention have been described above, but the present invention is not limited to the embodiments. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the invention. The invention is not limited by the foregoing description, but is only limited by the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view showing the arrangement of a substrate processing apparatus. Fig. 2 is a schematic configuration diagram of an electrolytic composite polishing apparatus. Figure 3 is a cross-sectional view of the substrate head. Figure 4 is a bottom view of the substrate head. ❹ Fig. 5A is a longitudinal sectional view showing an important part of the electrolytic composite polishing apparatus. Fig. 5B is a longitudinal sectional view schematically showing an important part of the electrolytic composite polishing apparatus. Fig. 6A is an explanatory view of electrolytic composite polishing. - Figure 6B is an explanatory diagram of electrolytic composite grinding. Fig. 6C is an explanatory view of electrolytic composite polishing. Figure 7 shows the relationship between the potential of the conductive film and the current density.

Fig. 8A is an explanatory view showing a state in which a protective film is formed when a voltage of each region is applied, and this figure shows a case of an α region. Fig. 8 is an explanatory view showing a state in which a protective film is formed when a voltage of each region is applied, and this figure shows a case of a cold region. Fig. 8C is an explanatory view showing the state of formation of a protective film when voltages of respective regions are applied. This figure shows the case of 7 regions. Fig. 9 is a graph showing the relationship between the applied voltage 舆 current 52 320663 200936309 density when the pH of the electrolyte is changed. Fig. ίο is a graph showing the relationship between the applied voltage and the current density when the rotational speed of the polishing pad is changed. Fig. 11 is a longitudinal sectional view schematically showing an important part of the chemical mechanical polishing apparatus. Fig. 12A is an explanatory view of electrolytic composite polishing. Fig. 12B is an explanatory view of electrolytic composite polishing. Fig. 12C is an explanatory view of electrolytic composite polishing. ❹ Fig. 13 is a plan view showing another configuration of the polishing table. [Description of main component symbols] 1 substrate head 2 substrate head body 2a housing portion 2b pressure piece support portion 2c sealing portion 2d recess portion 3 buckle 4 Pressure piece 8 Central pocket 9 Annular tube 10 Universal joint part 11 Substrate head drive shaft 11a Recessed part 12 Bearing ball 21 to 25 Pressure chamber 31, 33 to 36 Flow path 41 Opening portion 42 Projection portion 43 Flow path 50 Electrolyte 52 Grinding Pulp 55, 56 screw 62 interlayer insulation film 53 320663 200936309

63, 67 concave portion 64 66 conductive film 70 to 72 81, 91 elastic film 82 82a, 92a screw hole 92 100 polishing table 101 101a through hole 102 102a supply port 110 111 substrate head cylinder 112 113' 116 timing pulley 114 115 Gauge belt 117 120 compressed air source 121 200 travel mechanism 202, 208 204 substrate IE 206 210 rotary conveyor 212 214 cleaning unit 218 222 sink 224, 226 228 sensor coil 250 252 power supply 254 254a cover 254b 255 communication hole 256 258A first electrolyte receiving port 258B 262 electrical contact 264 300 substrate processing device 310 Cl central portion C2 group barrier protective film + central bag holder annular tube holder grinding 塾 electrolyte supply nozzle oscillating arm rotating cylinder substrate head motor axis

Vacuum source transfer robot substrate station Drying unit trimmer ITM Electrolytic composite grinding device support member bottom member communication groove second electrolyte receiving port power supply electrode control portion intermediate portion 320663 54 200936309 C3 peripheral portion C4 上 upper segment L Κ1 to Κ3 cathode RE1 W Sub-section peripheral portion RE6 regulator

❹ 55 320663

Claims (1)

200936309 VII. Patent application scope: 1. An electrolytic composite grinding method is to press the substrate surface with a predetermined contact surface pressure by contacting the electrolyte with a conductive film formed on the surface of the substrate and applying a voltage to the conductive film. An electrolytic composite polishing method of pressing the polishing pad while moving the substrate and the polishing pad to polish the surface of the conductive film, wherein the electrolyte is at a pH of 4 to 10, and the contact surface is pressed When the voltage is increased to @ by the state of 0, the voltage whose current density is changed from the increase to the decrease is taken as the minimum voltage, and when the voltage is increased in a state where the contact surface pressure is a finite value, the current density is decreased from the increase. The surface of the conductive film is polished while maintaining the voltage at a voltage not lower than the minimum voltage and the maximum voltage or lower. 2. An electrolytic composite polishing method in which a surface of the substrate is pressed to a polishing pad with a predetermined contact surface pressure by bringing an electrolyte into contact with a conductive film formed on a surface of the substrate and applying a voltage to the conductive film. An electrolytic composite polishing method for simultaneously polishing the surface of the conductive film while moving the substrate and the polishing pad, wherein the electrolyte is at a pH of 4 to 10, and the contact surface is pressed to a pressure of 0. When the voltage is increased, the voltage whose current density is changed from the increase to the decrease is taken as the minimum voltage, and when the voltage is increased in a state where the contact surface pressure is a finite value, the current density is changed from the increase to the decrease voltage as the maximum power. 320663 200936309 The surface of the conductive film is polished while maintaining the voltage above the minimum voltage and below the maximum voltage. 3. The electrolytic composite polishing method according to claim 1 or 2, wherein the polishing rate of the conductive film is controlled by adjusting the pH of the electrolyte. 4. The electrolytic composite polishing method according to claim 1 or 2, wherein the electrolytic solution contains an additive which reacts with the conductive film to form an electrical insulating material, and adjusts the concentration of the additive. The polishing rate of the aforementioned conductive film is controlled. 5. The electrolytic composite polishing method according to claim 1 or 2, wherein the polishing rate of the conductive film is controlled by adjusting a rotation speed of the polishing pad. 6. The electrolytic composite polishing method according to claim 1 or 2, wherein the conductive film is a tungsten film. 7. A polishing method of polishing a conductive film formed by polishing a substrate formed on a surface of the substrate while pressing a substrate surface to a polishing pad with a predetermined contact surface pressure to move the substrate and the polishing pad. In the protective film forming step, the protective film forming step is performed by moving the electrolyte to the conductive film while applying a voltage while moving the substrate and the polishing pad relative to each other. When the voltage is increased, the current density is changed from the increased decrease to the voltage that is no longer reduced as the threshold voltage, 57 320663 200936309, and before the grinding process, the substrate is not in contact with the polishing pad, A protective film is formed on the surface of the conductive film by bringing the electrolytic solution into contact with the conductive film while applying a voltage equal to or higher than the threshold voltage. 8. The polishing method according to claim 7, wherein the polishing step is a chemical mechanical polishing step or an electrolytic composite polishing step. 9. The method of claim 7, wherein the conductive film is a crane film. ❿ 10. An electrolytic composite polishing method in which a surface of the substrate is pressed to a polishing pad at a predetermined contact surface pressure while bringing an electrolytic solution into contact with a metal film formed on a surface of the substrate and applying a voltage to the metal film. An electrolytic composite polishing method for polishing a surface of the metal film by relatively moving the substrate and the polishing pad, wherein: the electrolyte solution has a pH of 4 to 10, and the metal film is a bottom film and a resistance ratio of the lower layer. The electroconductive composite polishing method comprises: a step of removing the conductive film in the vicinity of an application point of the voltage, exposing the underlying film, and exposing or exposing the underlying film; In the step of increasing the voltage, the step of increasing the voltage is to increase the current density from an increase to a decrease when the substrate is moved relative to the polishing crucible while the contact surface pressure is zero. Limiting the voltage, and increasing the voltage to the voltage of the exposed area of the underlying film 58 320663 200936309 Exceed the aforementioned threshold voltage. 11. The electrolytic composite polishing method according to claim 10, wherein the step of increasing the voltage is: when the voltage is increased in a state where the contact voltage is a finite value, the current density is decreased from increasing to no longer The reduced voltage is used as the maximum voltage, and the voltage is increased so that the voltage of the region outside the exposed region of the underlying film exceeds the threshold voltage and is at the maximum voltage. 12. The electrolytic composite polishing method according to claim 10, wherein the step of exposing the under film is to press the contact surface between the substrate and the polishing pad in a region in the vicinity of the application point, as compared with the application The aforementioned contact surface pressure in the region other than the region near the point is high. 13. The electrolytic composite polishing method according to claim 10, wherein the step of exposing the underlayer is such that a counter electrode facing the substrate is a plurality of concentrically arranged on the same plane The divided electrode formed by the small electrode controls the voltage of the split electrode so that the frequency of the opposite direction to the outer portion of the substrate is higher, so that the polishing speed is increased. 14. The electrolytic composite polishing method according to claim 10, wherein the polishing is performed while measuring the residual film thickness of the conductive film by an eddy current method. 15. The electrolytic composite polishing method according to claim 10, wherein the conductive film is a town film. 59 320663 200936309 16. An electrolytic composite polishing method in which a surface of the substrate is pressed to a predetermined contact surface pressure by bringing an electrolytic solution into contact with a metal film formed on a surface of the substrate and applying a voltage to the metal film. An electrolytic composite polishing method for polishing a surface of the metal film while the substrate is simultaneously moved relative to the polishing pad, wherein the electrolyte solution is a pH 4 to 10, and the metal film is a lower layer film and a resistor. The electrolytic composite polishing method comprises: a step of disposing the voltage application point on a peripheral portion of the substrate, and removing the conductive film on the peripheral portion to expose the base film. And a step of moving the application point of the voltage from the peripheral edge portion of the substrate to the central portion to expose the base film after the process. 17. An electrolytic composite polishing method in which a surface of the substrate is pressed to a polishing pad at a predetermined contact surface pressure while contacting an electrolytic solution with a metal film formed on a surface of the substrate and applying a voltage to the metal film. An electrolytic composite polishing method for polishing a surface of the metal film by relatively moving the substrate and the polishing pad, wherein the electrolyte solution has a pH of 4 to 10, and the metal film is composed of a lower layer of a base film and a resistor. a method of forming a conductive film having a small upper layer, wherein the electrolytic composite polishing method includes: a step of disposing the voltage application point on a peripheral portion of the substrate, and first removing the conductive film on the peripheral portion to expose the base film; Then, the step of increasing the voltage is performed by moving the application point of the voltage from the peripheral portion of the substrate 60 320663 200936309 toward the center portion to expose the base film, and the step of increasing the voltage after the base film is exposed or exposed. System: in order to move the aforementioned substrate and the aforementioned polishing pad while pressing the contact surface into a 〇 Temporal increase the voltage, current density increases from the converted voltage decreases as the threshold voltage, the voltage is increased to the base film so that the exposed area exceeds the voltage threshold voltage. 18. The electrolytic composite polishing method according to claim 1 or 2, wherein the voltage applied to the conductive film is a positive voltage. 19. The polishing method of claim 7, wherein the voltage applied to the conductive film is a positive voltage. 61 320663